The heart of a computer is a magnetic hard disk drive (HDD) which typically includes a rotating magnetic disk, a slider that has read and write heads, a suspension arm above the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected circular tracks on the rotating disk. The suspension arm biases the slider into contact with the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent an air bearing surface (ABS) of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing the write and read heads are employed for writing magnetic impressions to and reading magnetic signal fields from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
Demand has grown rapidly for storing images, music, and the like in hard disk drives, in the cases of video recorders with hard disk drives attached thereto, TVs with hard disk drives mounted therein, and so forth.
The volume of information processing in the information age is increasing rapidly. In particular, HDDs have been desired to store more information in its limited area and volume. A technical approach to this desire is to increase the capacity by increasing the recording density of the HDD. To achieve higher recording density, further miniaturization of recording bits is effective, which in turn typically requires the design of smaller and smaller components. The further miniaturization of the various components, however, presents its own set of challenges and obstacles.
The width of a recording track may be reduced in order to substantially increase the surface area recording density, however, reducing the recording track width causes the magnetic field generated on a recording medium from a lead end of a main magnetic pole to be reduced.
In a magnetic disk apparatus, reading is performed on a wide area from an inner circumference to an outer circumference in a magnetic recording medium. In the inner circumference and the outer circumference of the magnetic recording medium, however, the magnetic head performs the reading with a skew angle of about 0-20° with respect to a tangent line to the rotational direction of the magnetic recording medium. If the shape of the media facing surface in the main magnetic pole is rectangular, then a problem occurs in that the adjacent tracks tend to be removed.
In order to prevent this problem, conventional products use a main magnetic pole of a so-called reversed trapezoid shape in which the width of the leading side of the main magnetic pole is formed narrower than that of a trailing side of the main magnetic pole so as to correspond to the narrower track width. Further, in order to improve the density of the surface area for recording, it is required that the track widths be reduced narrowly while a track part of the main magnetic pole defining the recording track width is kept at the reversed trapezoidal shape corresponding to the skew angle.
In order to improve the density of the surface area for recording, it is essential to reduce the track width. However solutions for the resulting problem of a reduction in the recording magnetic field have been elusive.
Therefore, it would be desirable to provide a magnetic recording head structure, and manufacturing method thereof, in which overwriting of adjacent tracks is prevented while retaining a high magnetic field intensity and good magnetic field inclination with a high density of surface area recording.